Unverified Commit 31acceb9 authored by Christian Brauner's avatar Christian Brauner Committed by Christian Brauner (Microsoft)
Browse files

ovl: use posix acl api 



Now that posix acls have a proper api us it to copy them.

All filesystems that can serve as lower or upper layers for overlayfs
have gained support for the new posix acl api in previous patches.
So switch all internal overlayfs codepaths for copying posix acls to the
new posix acl api.

Acked-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
parent 0e641857

fs/overlayfs/copy_up.c

+38 −0
Original line number Diff line number Diff line
@@ -44,6 +44,35 @@ static bool ovl_must_copy_xattr(const char *name) 
	       !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN);

}



static int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path,

			struct dentry *dentry, const char *acl_name)

{

	int err;

	struct posix_acl *clone, *real_acl = NULL;



	real_acl = ovl_get_acl_path(path, acl_name, false);

	if (!real_acl)

		return 0;



	if (IS_ERR(real_acl)) {

		err = PTR_ERR(real_acl);

		if (err == -ENODATA || err == -EOPNOTSUPP)

			return 0;

		return err;

	}



	clone = posix_acl_clone(real_acl, GFP_KERNEL);

	posix_acl_release(real_acl); /* release original acl */

	if (!clone)

		return -ENOMEM;



	err = ovl_do_set_acl(ofs, dentry, acl_name, clone);



	/* release cloned acl */

	posix_acl_release(clone);

	return err;

}



int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new)

{

	struct dentry *old = oldpath->dentry;
@@ -93,6 +122,15 @@ int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct de 
			error = 0;

			continue; /* Discard */

		}



		if (is_posix_acl_xattr(name)) {

			error = ovl_copy_acl(OVL_FS(sb), oldpath, new, name);

			if (!error)

				continue;

			/* POSIX ACLs must be copied. */

			break;

		}



retry:

		size = ovl_do_getxattr(oldpath, name, value, value_size);

		if (size == -ERANGE)

fs/overlayfs/dir.c

+2 −18
Original line number Diff line number Diff line
@@ -435,28 +435,12 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, 
}



static int ovl_set_upper_acl(struct ovl_fs *ofs, struct dentry *upperdentry,

			     const char *name, const struct posix_acl *acl)

			     const char *acl_name, struct posix_acl *acl)

{

	void *buffer;

	size_t size;

	int err;



	if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl)

		return 0;



	size = posix_acl_xattr_size(acl->a_count);

	buffer = kmalloc(size, GFP_KERNEL);

	if (!buffer)

		return -ENOMEM;



	err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);

	if (err < 0)

		goto out_free;



	err = ovl_do_setxattr(ofs, upperdentry, name, buffer, size, XATTR_CREATE);

out_free:

	kfree(buffer);

	return err;

	return ovl_do_set_acl(ofs, upperdentry, acl_name, acl);

}



static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,

fs/overlayfs/inode.c

+2 −2
Original line number Diff line number Diff line
@@ -510,7 +510,7 @@ static void ovl_idmap_posix_acl(const struct inode *realinode, 
 * Until we have made a decision allow this helper to take the @noperm

 * argument. We should hopefully be able to remove it soon.

 */

static struct posix_acl *ovl_get_acl_path(const struct path *path,

struct posix_acl *ovl_get_acl_path(const struct path *path,

				   const char *acl_name, bool noperm)

{

	struct posix_acl *real_acl, *clone;

fs/overlayfs/overlayfs.h

+8 −0
Original line number Diff line number Diff line
@@ -623,10 +623,18 @@ static inline struct posix_acl *ovl_get_acl(struct user_namespace *mnt_userns, 
}

int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,

		struct posix_acl *acl, int type);

struct posix_acl *ovl_get_acl_path(const struct path *path,

				   const char *acl_name, bool noperm);

#else

#define ovl_get_inode_acl	NULL

#define ovl_get_acl		NULL

#define ovl_set_acl		NULL

static inline struct posix_acl *ovl_get_acl_path(const struct path *path,

						 const char *acl_name,

						 bool noperm)

{

	return NULL;

}

#endif



int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);

fs/overlayfs/super.c

+2 −4
Original line number Diff line number Diff line
@@ -813,13 +813,11 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs, 
		 * allowed as upper are limited to "normal" ones, where checking

		 * for the above two errors is sufficient.

		 */

		err = ovl_do_removexattr(ofs, work,

					 XATTR_NAME_POSIX_ACL_DEFAULT);

		err = ovl_do_remove_acl(ofs, work, XATTR_NAME_POSIX_ACL_DEFAULT);

		if (err && err != -ENODATA && err != -EOPNOTSUPP)

			goto out_dput;



		err = ovl_do_removexattr(ofs, work,

					 XATTR_NAME_POSIX_ACL_ACCESS);

		err = ovl_do_remove_acl(ofs, work, XATTR_NAME_POSIX_ACL_ACCESS);

		if (err && err != -ENODATA && err != -EOPNOTSUPP)

			goto out_dput;